take off take in take up take away

Câu hỏi :

Unfortunately, diets don‘t work for most people. They do lose weight but then go off the diet and put it back. Building a sensible diet and exercise plan is the key (1)_____ maintaining a consistent weight. You need to figure out how many calories you need in a day and how many you actually (2)______. The next step is   to add exercise (3)_____ you can raise the number of calories you can consume per day.